FIG. 1 is a schematic diagram illustrating an example of a hot standby dual monitor Operation System (OpS) 10 according to a related art example.
As illustrated in FIG. 1, the operation system 10 includes clients 11-1 to 11- m of a client system for receiving a service request (e.g., monitor request, control request) from an operator and main and auxiliary servers 13, 14 of a server system, being connected to corresponding clients via a monitor network 12, for executing input service requests.
The servers 13, 14 and transmission apparatuses (NE: Network Element) 16-1 to 16-n are connected to each other via a monitor network 15. The transmission apparatuses (NE: Network Element) 16-1 to 16-n are subject to monitoring and control by the servers 13, 14. The network elements 16-1 to 16n constitute a network that transmits/receives main signals.
As a countermeasure against a disaster, the hot standby dual monitor operation system uses multisites in which the main server 13 and the auxiliary server 14 are allocated at distant locations. In order to maintain operability even during maintenance of the servers 13, 14 or a case where a failure occurs in one of the dual system, the main and auxiliary servers 13, 14 include a configuration database 13a, 14a and a monitor data base 13b, 14b, respectively. Thereby, the servers 13, 14 are operable 24 hours a day and 365 days a year.
The configuration database 13a, 14a use a multi-master replication function for synchronizing data of the main server 13 and data of the auxiliary server 14. In order to achieve dual monitoring, data is managed by the monitor databases 13b, 14b of the servers 13, 14. Since dual monitoring is performed where monitoring is performed separately (independently) by the main and auxiliary servers 13, 14, alarm data such as TRAP is redundantly managed and an alarm (e.g., an alarm of the monitor network 15 or an alarm of the network elements 16-1 to 16-n) is prevented from being undetected to a maximal degree. Thus, monitoring performance is improved.
There is known a technology of a duplex communication control system including communication control apparatuses A, B of active and standby servers, duplicated shared (common) disk apparatuses ca, cb, and internal disk apparatuses ia, ib provided inside the communication control apparatuses A, B (see, for example, Japanese Laid-Open Patent Publication No. 2006-107074). With the technology, among service data stored in the shared disk apparatuses ca, cb, only service requisite data is stored into the internal disk apparatuses ia, ib, so that the communication control apparatus A of the active system can use the service requisite data stored in the internal disk apparatus is during a failure.
Further, there is known a technology of an automatic failure recovery communication system including a process control part for controlling all processes of the system (see, for example, Japanese Laid-Open Patent Publication No. 2000-215074). The system is provided with an original process having operation management programs for system operation and system management and a clone process having necessary irreducible operation management programs among the operation management programs of the original process in which periodic communications are performed between the original process and the clone process.
Further, there is known a technology of a decentralized type communication system including plural communication process servers for performing a set of communication processes, a log server including a dual disk for storing process log data of each of the communication process servers, and a monitor server for monitoring the communication process servers and the log server and performing restart control when a failure occurs (see, for example, Japanese Laid-Open Patent Publication No. 8-79246).
Further, there is known a technology of an image process system server including a backup server in which the performing of processes and operations is switched to the backup server when detecting that a main server is inoperable (see, for example, Japanese National Publication of International Patent Application No. 2008-538242).
In order to maintain the order for executing update transactions of the configuration database in the hot standby dual monitor operation system, the updating of the configuration database is allowed to be performed by the active system (main server or auxiliary server) alone. Then, by transmitting a query to the inactive (standby) server (auxiliary server or main server) with a replication function, synchronization between the data of the configuration database of the active server and the data of the configuration database of the inactive server can be performed.
In a case where there is a failure in the active server 13 or a case where the inactive server 14 cannot be accessed due to, for example, hardware failure or application defects as illustrated in FIG. 2, the inactive server cannot switch to an active server until there is confirmation that all of the update transactions of the active server 13 have been transmitted to the inactive server 14. This is to ensure consistency between the configuration databases 13a, 14a and to prevent a deadlock of data from occurring.
Accordingly, by preventing the inactive server from performing a process of registering data or a process of controlling the transmission apparatus along with the updating of the configuration database (single system operation), consistency between configuration databases can be ensured. This, however, leads to a problem where the user is compelled to use a system in which the inactive server is only allowed to perform a monitoring process.